Combined with the technologies of data acquisition and storage, a fault recording system based on virtual instrument technology for electric vehicle charging post is designed using LabVIEW. The system estimates whether fault occurs by digitally filtering and analyzing the data acquired bySdata acquisition card. In the event of a fault, waveforms of electrical quantities before, during, and after fault will be recorded to files automatically and accurately. With fault wave reproduction function, data in record files can be drawn in waveform graph. So, changes of electrical quantities in the fault state are obvious. Fault recorder provides a recording and analyzing tool for fault analysis, performance test and power quality monitoring of charging post.